Mobile fi ltration units

UFM 041Mobile fi ltration unit 34 l/min fl ow rate

Mobile fi ltration units95

Introduction 10

HYDRAULIC FLUIDS

FLUIDS CONTAMINATION

EFFECTS OF CONTAMINATION ON HYDRAULIC COMPONENTS

MEASURING THE SOLID CONTAMINATION LEVEL

RECOMMENDED CONTAMINATION CLASSES

WATER IN HYDRAULIC AND LUBRICATING FLUIDS

12

12

12

13

16

16

Page

Contamination managementINDEX

Introduction

1

2

3

4

5

6

Introduction11

CONTAMINATION MANAGEMENT

HYDRAULIC FLUIDS

The � uid is the vector that transmits power, energy within an oleodynamic circuit.In addition to transmitting energy through the circuit, it also performs additional functions such as lubrication, protection and cooling of the surfaces.The classi� cation of � uids used in hydraulic systems is coded in many regulatory references, different Standards.

The most popular classi� cation criterion divides them into the following families:- MINERAL OILS Commonly used oil deriving � uids.

- FIRE RESISTANT FLUIDS Fluids with intrinsic characteristics of incombustibility or high � ash point.

- SYNTHETIC FLUIDS Modi� ed chemical products to obtain speci� c optimized features.

- ECOLOGICAL FLUIDS Synthetic or vegetable origin � uids with high biodegradability characteristics.

The choice of � uid for an hydraulic system must take into account several parameters.These parameters can adversely affect the performance of an hydraulic system, causing delay in the controls, pump cavitation, excessive absorption, excessive temperature rise, ef� ciency reduction, increased drainage, wear, jam/block or air intake in the plant.

The main properties that characterize hydraulic � uids and affect their choice are:- DYNAMIC VISCOSITY It identi� es the � uid’s resistance to sliding due to the impact of the particles forming it.

- CINEMATIC VISCOSITY It is a widespread formal dimension in the hydraulic � eld. It is calculated with the ratio between the dynamic viscosity and the fluid density. Cinematic viscosity varies with temperature and pressure variations.

- VISCOSITY INDEX This value expresses the ability of a fluid to maintain viscosity when the temperature changes. A high viscosity index indicates the fluid’s ability to limit viscosity variations by varying the temperature.

- FILTERABILITY INDEX It is the value that indicates the ability of a fluid to cross the filter materials. A low � lterability index could cause premature clogging of the � lter material.

- WORKING TEMPERATURE Working temperature affects the fundamental characteristics of the fluid. As already seen, some � uid characteristics, such as cinematic viscosity, vary with the temperature variation. When choosing a hydraulic oil, must therefore be taken into account of the environmental conditions in which the machine will operate.

- COMPRESSIBILITY MODULE Every � uid subjected to a pressure contracts, increasing its density. The compressibility module identifies the increase in pressure required to cause a corresponding increase in density.

- HYDROLYTIC STABILITY It is the characteristic that prevents galvanic pairs that can cause wear in the plant/system.

- ANTIOXIDANT STABILITY AND WEAR PROTECTION These features translate into the capacity of a hydraulic oil to avoid corrosion of metal elements inside the system.

- HEAT TRANSFER CAPACITY It is the characteristic that indicates the capacity of hydraulic oil to exchange heat with the surfaces and then cool them.

FLUID CONTAMINATION

Whatever the nature and properties of fluids, they are inevitably subject to contamination. Fluid contamination can have two origins:

- INITIAL CONTAMINATION Caused by the introduction of contaminated � uid into the circuit, or by incorrect storage, transport or transfer operations.

- PROGRESSIVE CONTAMINATION Caused by factors related to the operation of the system, such as metal surface wear, sealing wear, oxidation or degradation of the fluid, the introduction of contaminants during maintenance, corrosion due to chemical or electrochemical action between fluid and components, cavitation. The contamination of hydraulic systems can be of different nature:

- SOLID CONTAMINATION For example rust, slag, metal particles, � bers, rubber particles, paint particles - or additives

- LIQUID CONTAMINATION For example, the presence of water due to condensation or external in� ltration or acids

- GASEOUS CONTAMINATION For example, the presence of air due to inadequate oil level in the tank, drainage in suction ducts, incorrect sizing of tubes or tanks.

EFFECTS OF CONTAMINATION ON HYDRAULIC COMPONENTS

Solid contamination is recognized as the main cause of malfunction, failure and early degradation in hydraulic systems. It is impossible to delete it completely, but it can be effectively controlled by appropriate devices.

Solid contamination mainly causes surface damage and component wear.

EFFECTS OF CONTAMINATION ON HYDRAULIC 3

CONTAMINATION IN PRESENCE OF LARGE TOLERANCES

CONTAMINATION IN PRESENCE OF NARROW TOLERANCES

FLUID CONTAMINATION2

HYDRAULIC FLUIDS1

Introduction 12

CONTAMINATION MANAGEMENT

- SURFACE EROSION Cause of leakage through mechanical seals, reduction of system performance, variation in adjustment of control components, failures.

- ADHESION OF MOVING PARTS Cause of failure due to lack of lubrication.

- DAMAGES DUE TO FATIGUE Cause of breakdowns and components breakdown.stem performance, failures.

Liquid contamination mainly results in decay of lubrication performance and protection of � uid surfaces.

DISSOLVED WATER

- INCREASING FLUID ACIDITY Cause of surface corrosion and premature � uid oxidation

- GALVANIC COUPLE AT HIGH TEMPERATURES Cause of corrosion

FREE WATER - ADDITIONAL EFFECTS

- DECAY OF LUBRICANT PERFORMANCE Cause of rust and sludge formation, metal corrosion and increased solid contamination

- BATTERY COLONY CREATION Cause of worsening in the � lterability feature

- ICE CREATION AT LOW TEMPERATURES Cause damage to the surface

- ADDITIVE DEPLETION Free water retains polar additives

Gaseous contamination mainly results in decay of system performance.

- CUSHION SUSPENSION Cause of increased noise and cavitation.

- FLUID OXIDATION Cause of corrosion acceleration of metal parts.

- MODIFICATION OF FLUID PROPERTIES (COMPRESSIBILITY MODULE, DENSITY, VISCOSITY) Cause of system’s reduction of ef� ciency and of control. It is easy to understand how a system without proper contamination management is subject to higher costs than a system that is provided.

- MAINTENANCE Maintenance activities, spare parts, machine stop costs

- ENERGY AND EFFICIENCY Efficiency and performance reduction due to friction, drainage, cavitation.

MEASURING THE SOLID CONTAMINATION LEVEL

The level of contamination of a system identi� es the amount of contaminant contained in a � uid.This parameter refers to a unit volume of � uid.The level of contamination may be different at different points in the system.From the information in the previous paragraphs it is also apparent that the level of contamination is heavily in� uenced by the working conditions of the system, by its working years and by the environmental conditions.

What is the size of the contaminating particles that we must handle in our hydraulic circuit?

Contamination level analysis is signi� cant only if performed with a uniform and repeatable method, conducted with standard test methods and suitably calibrated equipment.To this end, ISO has issued a set of standards that allow tests to be conducted and express the measured values in the following ways.

- GRAVIMETRIC LEVEL - ISO 4405

The level of contamination is de� ned by checking the weight of particles collected by a laboratory membrane. The membrane must be cleaned, dried and desiccated, with � uid and conditions de� ned by the Standard.The volume of � uid is � ltered through the membrane by using a suitable suction system. The weight of the contaminant is determined by checking the weight of the membrane before and after the � uid � ltration.

HUMAN HAIR(75 µm)

MINIMUM DIMENSION VISIBLE HUMAN EYES

(40 µm)

TYPICAL CONTAMINANT DIMENSION IN A

HYDRAULIC CIRCUIT(4÷14 µm)

MEASURING THE SOLID CONTAMINATION LEVEL4

ABRASION

ADHESION

EROSION

FATIGUE

Introduction13

CONTAMINATION MANAGEMENT

- CUMULATIVE DISTRIBUTION OF THE PARTICLES SIZE - ISO 4406

The level of contamination is defined by counting the number of particles of certain dimensions per unit of volume of fluid. Measurement is performed by Automatic Particle Counters (APC).Following the count, the contamination classes are determined, corresponding to the number of particles detected in the unit of fluid.The most common classification methods follow ISO 4406 and SAE AS 4059 (Aerospace Sector) regulations.NAS 1638 is still used although obsolete.

Classification example according to ISO 4406The code refers to the number of particles of the same size or greater than 4, 6 or 14 μm in a 1 ml fluid.

ISO 4406:2017 Cleanliness Code SystemMicroscope counting examines the particles differently to APCs and the code is given with two scale numbers only.These are at 5 µm and 15 µm equivalent to the 6 µm(c) and 14 µm(c) of APCs.

Num

ber

of p

arti

cles

per

100

ml l

arge

r th

an in

dica

ted

size

Cleanliness Code Chart with 100 ml sample volume

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

1.6

8

8

8

4

4

4

4 65

1415

New ISO 4406 standard µm(c) Old standard

ISO

4 C

ode

num

bers

2

2

2

1

10

102

103

104

105

106

107

5

5

6.4

6.4

2.5

2.5

3.2

3.2

1.3

1.3

1.6

1.6

Example Code22/19/1422/19/14

> 4 µm(c) = 350 particles> 6 µm(c) = 100 particles> 14 µm(c) = 25 particles16 / 14 / 12

1 300 000640 000320 000160 00080 00040 00020 00010 0005 0002 5001 300640320160804020105

2.51.30.640.320.160.080.040.020.01

0

2 500 0001 300 000640 000320 000160 00080 00040 00020 00010 0005 0002 5001 300640320160804020105

2.51.30.640.320.160.080.040.020.01

282726252423222120191817161514131211109876543210

Class Number of particles per ml

Over Up to

Introduction 14

- CUMULATIVE DISTRIBUTION OF THE PARTICLES SIZE - SAE AS 4059-1 and SAE AS 4059-2

Classification example according to SAE AS 4059-1 and SAE AS 4059-2The code, prepared for the aerospace industry, is based on the size, quantity, and particle spacing in a 100 ml fluid sample. The contamination classes are defined by numeric codes, the size of the contaminant is identified by letters (A-F).

It can be made a differential measurement (Table 1) or a cumulative measurement (Table 2)

- CLASSES OF CONTAMINATION ACCORDING TO NAS 1638 (January 1964)

The NAS system was originally developed in 1964 to define contamination classes for the contamination contained within aircraft components. The application of this standard was extended to industrial hydraulic systems simply because nothing else existed at the time.The coding system defines the maximum numbers permitted of 100ml volume at various size intervals (differential counts) rather than using cumulative counts as in ISO 4406:1999. Although there is no guidance given in the standard on how to quote the levels, most industrial users quote a single code which is thehighest recorded in all sizes and this convention is used on MP Filtri APC’s.

The contamination classes are defined by a number (from 00 to 12) which indicates the maximum number of particles per 100 ml, counted on a differential basis, in a given size bracket.

- CUMULATIVE DISTRIBUTION OF THE PARTICLES SIZE - ISO 4407

The level of contamination is defined by counting the number of particles collected by a laboratory membrane per unit of fluid volume. The measurement is done by a microscope.The membrane must be cleaned, dried and desiccated, with fluid and conditions defined by the Standard. The fluid volume is filtered through the membrane, using a suitable suction system.The level of contamination is identified by dividing the membrane into a predefined number of areas and by counting the contaminant particles using a suitable laboratory microscope.

CONTAMINATION MANAGEMENT

195390780

1 5603 1206 250

12 50025 00050 000

100 000200 000400 000800 000

1 600 0003 200 000

76152304609

1 2172 4324 8649 731

19 46238 92477 849

155 698311 396622 792

1 245 584

142754

109217432864

1 7313 4626 924

13 84927 69855 396

110 792221 584

35

10203976

152306612

1 2242 4494 8989 796

19 59239 184

11247

132653

106212424848

1 6963 3926 784

00011248

163264

128256512

1 024

000000123456789101112

Class Dimension of contaminant

>4 µm(c)A

>6 µm(c)B

>14 µm(c)C

>21 µm(c)D

>38 µm(c)E

>70 µm(c)F

Table 2 - Class for cumulative measurement

125250500

1 0002 0004 0008 000

16 00032 00064 000

128 000256 000512 000

1 024 000

224489

178356712

1 4252 8505 700

11 40022 80045 60091 200

182 400

48

163263

126253506

1 0122 0254 0508 100

16 20032 400

1236

11224590

180360720

1 4402 8805 760

0011248

163264

128256512

1 024

000123456789101112

Class Dimension of contaminant

6÷14 µm(c) 14÷21 µm(c) 21÷38 µm(c) 38÷70 µm(c) >70 µm(c)

Table 1 - Class for differential measurement

6÷14 µm(c) = 15 000 particles14÷21 µm(c) = 2 200 particles21÷38 µm(c) = 200 particles38÷70 µm(c) = 35 particles> 70 µm(c) = 3 particlesClass 6

Size Range Classes (in microns)

Maximum Contamination Limits per 100 ml

000123456789

101112

125250500

1 0002 0004 0008 000

16 00032 00064 000

128 000256 000512 000

1 024 000

224489

178356712

1 4252 8505 700

11 40022 80045 60091 200

182 400

48

163263

126253506

1 0122 0254 0508 100

16 20032 400

1236

11224590

180360720

1 4402 8805 760

0011248

163264

128256512

1 024

5÷15 15÷25 25÷50 50÷100 >100Class

MICROSCOPE CONTROL AND MEASUREMENT

COMPARISON PHOTOGRAPH’S

18

ISO 4406:1999 Class 16/14/11

SAE AS4059E Table 1 Class 5

NAS 1638 Class 5

SAE AS4059E Table 2 Class 6A/5B/5C

1 graduation= 10 µm

Comparison Photograph’s for Contamination

www.mpfiltri.co.uk www.mpfiltri.com Condition Monitoring Division Group Headquarters 24

ISO 4406:1999 Class 22/20/17

SAE AS4059E Table 1 Class 11

NAS 1638 Class 11

SAE AS4059E Table 2 Class 12A/11B/11C

1 graduation= 10 µm

Comparison Photograph’s for Contamination

www.mpfiltri.co.uk www.mpfiltri.com Condition Monitoring Division Group Headquarters

ISO 4406:1999SAE AS4059E Table 1NAS 1638SAE AS4059E Table 2

Class 16/14/11Class 5Class 5Class 6A/5B/5C

Class 22/20/17Class 11Class 11Class 12A/11B/11C

1 graduation = 10µm

> 4 µm(c) = 45 000 particles> 6 µm(c) = 15 000 particles> 14 µm(c) = 1 500 particles> 21 µm(c) = 250 particles> 38 µm(c) = 15 particles> 70 µm(c) = 3 particleClass from 2F to 4E

5÷15 µm(c) = 42 000 particles15÷25 µm(c) = 2 200 particles25÷50 µm(c) = 150 particles50÷100 µm(c) = 18 particles> 100 µm(c) = 3 particlesClass NAS 8

Introduction15

CONTAMINATION MANAGEMENT

- CLEANLINESS CODE COMPARISON

Although ISO 4406:2017 standard is being used extensively within the hydraulics industry other standards are occasionally required and a comparison may be requested. The table below gives a very general comparison but often no direct comparison is possible due to the different classes and sizes involved.

RECOMMENDED CONTAMINATION CLASSES

Any are the nature and the properties of fl uids, they are inevitably subject to contamination. The level of contamination can be managed by using special components called fi lters.Hydraulic components builders, knowing the problem of contamination, recommend the fi ltration level appropriate to the use of their products.

Example of recommended contamination levels for pressures below 140 bar.

WATER IN HYDRAULIC AND LUBRICATING FLUIDS

Water Content

In mineral oils and non aqueous resistant fl uids water is undesirable. Mineral oil usually has a water content of 50-300 ppm (@40°C) which it can support without adverse consequences.Once the water content exceeds about 300ppm the oil starts to appear hazy. Above this level there is a danger of free water accumulating in the system in areas of low fl ow. This can lead to corrosion and accelerated wear.Similarly, fire resistant fluids have a natural water which may be different to mineral oil.

Saturation Levels

Since the effects of free (also emulsifi ed) water is more harmful than those of dissolved water, water levels should remain well below the saturation point.

However, even water in solution can cause damage and therefore every reasonable effort should be made to keep saturation levels as low as possible.There is no such thing as too little water. As a guideline, we recommend maintaining saturation levels below 50% in all equipment.

TYPICAL WATER SATURATION LEVEL FOR NEW OILSExamples:Hydraulic oil @ 30°C = 200ppm = 100% saturationHydraulic oil @ 65°C = 500ppm = 100% saturation

RECOMMENDED CONTAMINATION CLASSES5

6

23 / 21 / 18

22 / 20 / 17

21 / 19 / 16

20 / 18 / 15

19 / 17 / 14

18 / 16 / 13

17 / 15 / 12

16 / 14 / 11

15 / 13 / 10

14 / 12 / 09

13A / 12B / 12C

12A / 11B / 11C

11A / 10B / 10C

10A / 9B / 9B

9A / 8B / 8C

8A / 7B / 7C

7A / 6B / 6C

6A / 5B / 5C

5A / 4B / 4C

4A / 3B / 3C

12

11

10

9

8

7

6

5

4

3

12

11

10

9

8

7

6

5

4

3

ISO 4406:2017 SAE AS4059Table 2

SAE AS4059Table 1

NAS 1638

> 4 µm(c)6 µm(c)

14 µm(c)

> 4 µm(c)6 µm(c)

14 µm(c)

4-6 6-14

14-21 21-38 38-70 >70

5-1515-2525-50

50-100>100

Part

s pe

r m

illio

n

Temperature °C

20

200

400

600

030 40 50 60 70

Hydraulic oilGear oilTurbine oil

Saturation point

Emulsified

Dis

solv

ed w

ater

Free

wat

er

- 0%

- 25%

- 50%

- 75%

- 100%

Piston pumps with fi xed fl ow ratePiston pumps with variable fl ow rateVane pumps with fi xed fl ow rateVane pumps with variable fl owEnginesHydraulic cylindersActuatorsTest benchesCheck valveDirectional valvesFlow regulating valvesProportional valvesServo-valvesFlat bearingsBall bearingsISO 4406 CODERecommended fi ltration ßx(c)≥1.000

•

•

•

•

••

••

•

•

•

•

•••

20/18/15ß20(c)

>1000

17/15/12ß7(c)

>1000

19/17/14ß15(c) >1000

16/14/11ß7(c)

>1000

18/16/13ß10(c)

>1000

15/13/10ß5(c)

>1000

Introduction 16

W - Water and Temperature Sensing

“W” option, in MP Filtri Contamination Monitoring Products, indicates water content as a percentage of saturation and oil temperature in degrees centigrade. 100% RH corresponds to the point at which free water can exist in the fluid. i.e. the fluid is no longer able to hold the water in a dissolved solution.The sensor can help provide early indication of costly failure due to free water, including but not exclusive to:- Corrosion- Metal surface fatigue e.g. bearing failure- Reduced lubrication & load carrying characteristics

Different oils have different saturation levels and therefore RH (relative humidity) % is the best and most practical measurement.

Water absorber

Water is present everywhere, during storage, handling and servicing.

MP Filtri filter elements feature an absorbent media which protects hydraulic systems from both particulate and water contamination.MP Filtri’s filter element technology is available with inorganic microfiber media with a filtration rating 25 μm (therefore identified with media designation WA025, providing absolute filtration of solid particles to ßx(c) = 1000.Absorbent media is made by water absorbent fibres which increase in size during the absorption process.Free water is thus bonded to the filter media and completely removed from the system (it cannot even be squeezed out).

By removing water from your fluid power system, you can prevent such key problems as:- corrosion (metal etching)- loss of lubricant power- accelerated abrasive wear in hydraulic components- valve-locking- bearing fatigue- viscosity variance (reduction in lubricating properties)- additive precipitation and oil oxidation- increase in acidity level- increased electrical conductivity (loss of dielectric strength)- slow/weak response of control systems

Product availability - UFM Series: UFM 041 UFM 051 UFM 091 UFM 181 UFM 919

CONTAMINATION MANAGEMENT

Filter Media Absorber media layer

Fabric that absorbs water The Filter Media has absorbed water

>>>

CONTAMINATION MANAGEMENT

WIRE MESH FILTRATION PAPER FILTRATION MICROFIBER FILTRATION

The filtration efficiency of metallic mesh filtrations is defined as the maximum particle size that can pass through the meshes of the filtering grid. The efficiency of microfibre and paper filtration (ßx (C)) is defined through a lab test called Multipass Test. The efficiency value (ßx (C)) is defined as the ratio between the number of particles of certain dimensions detected upstream and downstream of the filter.

Upstream particles number > Xµm ------------------------------------------------- = ßx (C) Downstream particles number > Xµm

Test conditions, such as type of fluid to be used (MIL-H-5606), type of contaminant to be used (ISO MTD), fluid viscosity, test temperature, are determined by ISO 16889. In addition to the filtration efficiency value during the Multipass test, other important features, such as filtration stability (ß stability) and dirt holding capacity (DHC), are also tested. Poor filtration stability is the cause of the filtering quality worsening as the filter life rises. Low dirt holding capacity causes a reduction in the life of the filter.

Value (ßx (C)) 2 10 75 100 200 1000

Efficiency 50% 90% 98.7% 99% 99.5% 99.9%

Filtration ISO Standard Comparison

Beta x (C) > 1000 ISO 16889

Beta x > 200 ISO 4572

MP Filtri Filter media code

5 mic. (C) 3 mic. A03

7 mic. (C) 6 mic. A06

12 mic. (C) 12 mic. A10

21 mic. (C) 25 mic. A25

! / 10 14

Support pipe

Inner protective wire meshInner support layer

Filtration layer

Pre-filtration layerExternal protective wire meshExternal protective wire mesh

Water absorber layerInorganic microfiber mediaInner support layerInner protective wire mesh

Support pipe

Introduction17

UFM 041 GENERAL INFORMATION

Mobile fi ltration units

UFM 041 mobile fi ltration units suitable for fi lling and refi lling of fi ltered hydraulic fl uids and lubrication tanks.

The fi lter unit connected to off-line to the tank (recommended maximum volume of 350/500 L.), can be used as a support to the fi ltration plant on start-up for fast fl ushing action, either as additional fi ltration systems with a high incidence of contamination.

Continued use is recommended for the version with three phase electric motor.

Description

Features & Benefi ts- Compact size- Light- Easy to use- Easy maintenance- Reliable- Absolute fi ltration

>

Mobile fi ltration units 96

UFM 041GENERAL INFORMATION

Technical data

PumpGear pump

Electric Motor0.75 Kw 230 Volt single phase electric motor

0.75 Kw 400/230 Volt three phase electric motor

Flow (l/min)34 l/min - 1450 r.p.m.

Max. Operation Pressure5 bar

Viscosity rangeMin. operation 10 cSt

Max. operation 200 cSt

Max. only for cold start 800 cSt

Suction FilterType Y filtration 350 μm

Filtration Rating1/3/6/10/25 μm ß>1000 flow through the element In/Out

Bypass valveRating 2.5 bar

Fluid TemperatureFrom -10° to +80 °C

Ambient TemperatureFrom -20° to +45 °C

Protection ClassIP 55

SealNBR

Fluid CompatibilityMineral Oil & Synthetic Oil - Other on request

Suction hose lanceDN25 length 3000 mm DN/OD25 length 700 mm

Pressure hose lanceDN20 length 3000 mm DN/OD20 length 700 mm

Weight 45 kg

EquipmentVisual clogging indicator (gauge)

Standard

Mobile filtration units97

SeriesUFM

Size

Clogging indicator and particle counter

Electric motor

Seals

041

1

M

A

T

34 l/min

Filter element0 Without element

Manometer

230V single phase

NBR

400/230V three phase

Configuration example: UFM A 1 P011041 T O O

MR 250 4 A01 A P01MR 250 4 A03 A P01MR 250 4 A06 A P01MR 250 4 A10 A P01MR 250 4 A16 A P01MR 250 4 A25 A P01

MR 250 4 M25 A P01MR 250 4 M60 A P01

Inorganic microfibre Wire mesh element

Filtration surface

Option

1

P01Pxx

Standard

Option0 No options

MP Filtri standardCustomized

MOBILE FILTRATION UNIT UFM 041

Filtration element should be ordered separately

Designation & Ordering code

FILTRATION SURFACE - STANDARD

Multi-Layer water absorber

WATER REMOVAL - FILTRATION SURFACE - STANDARD

MR2504WA025AP01

UFM 041

Mobile filtration units 98

ARIA 620

Dimensions

HYDRAULIC CIRCUIT

UFM 041

Mobile filtration units99